HP-67 - 1909S02534 - Card reader advice requested

[albertofenini]

Hello Everyone,
after a bad moment in our lives with the loss of my father,
we re-opened our lab and started to work again on our toys.
Yesterday we restored an HP-67 that was in working condition but showing some wear,
you can see some pictures here :
HP-67 1909S02534 - Full restoration
However, the card reader, although rebuilt, it keeps giving an error message.
This is what RA and RB looks like :
   
   
What would you suggest to do ?
Thanks for helping us out !!!

[Massimo Gnerucci]

(01-27-2020 09:47 AM)albertofenini Wrote:  Hello Everyone,
after a bad moment in our lives with the loss of my father,
we re-opened our lab and started to work again on our toys.
Yesterday we restored an HP-67 that was in working condition but showing some wear,
you can see some pictures here :
HP-67 1909S02534 - Full restoration
However, the card reader, although rebuilt, it keeps giving an error message.
This is what RA and RB looks like :


What would you suggest to do ?
Thanks for helping us out !!!

Condoglianze per la tua perdita, Alberto.

Condolences for your loss, Alberto.

[albertofenini]

(01-27-2020 11:00 AM)Massimo Gnerucci Wrote:  

(01-27-2020 09:47 AM)albertofenini Wrote:  Hello Everyone,
after a bad moment in our lives with the loss of my father,
we re-opened our lab and started to work again on our toys.
Yesterday we restored an HP-67 that was in working condition but showing some wear,
you can see some pictures here :
HP-67 1909S02534 - Full restoration
However, the card reader, although rebuilt, it keeps giving an error message.
This is what RA and RB looks like :


What would you suggest to do ?
Thanks for helping us out !!!

Condoglianze per la tua perdita, Alberto.

Condolences for your loss, Alberto.

Thanks Massimo

[teenix]

(01-27-2020 09:47 AM)albertofenini Wrote:  Hello Everyone,
after a bad moment in our lives with the loss of my father,
we re-opened our lab and started to work again on our toys.
Yesterday we restored an HP-67 that was in working condition but showing some wear,
you can see some pictures here :
HP-67 1909S02534 - Full restoration
However, the card reader, although rebuilt, it keeps giving an error message.
This is what RA and RB looks like :


What would you suggest to do ?
Thanks for helping us out !!!

Hi Alberto,

Indeed a sad time. Memories are forever.

....

The only thing I can see is the timing of the signals looks skewed. They should overlap as in the attached read image.

The idea of this approach is to provide a self clocking mechanism for more reliable data transfers.

Why it would be skewed is a mystery, but it might just be oscilloscope timing.

Does it write ok?

cheers

Tony

[albertofenini]

(01-27-2020 11:26 AM)teenix Wrote:  

(01-27-2020 09:47 AM)albertofenini Wrote:  Hello Everyone,
after a bad moment in our lives with the loss of my father,
we re-opened our lab and started to work again on our toys.
Yesterday we restored an HP-67 that was in working condition but showing some wear,
you can see some pictures here :
HP-67 1909S02534 - Full restoration
However, the card reader, although rebuilt, it keeps giving an error message.
This is what RA and RB looks like :


What would you suggest to do ?
Thanks for helping us out !!!

Hi Alberto,

Indeed a sad time. Memories are forever.

....

The only thing I can see is the timing of the signals looks skewed. They should overlap as in the attached read image.

The idea of this approach is to provide a self clocking mechanism for more reliable data transfers.

Why it would be skewed is a mystery, but it might just be oscilloscope timing.

Does it write ok?

cheers

Tony

Thanks Tony,
they look a little dirty too so we were thinking of capacitors to be replaced,
we haven't tried to record and read on another unit, which is a good hint,we'll try it out
and keep posting !

Thanks for your words, Alberto

[Moggul]

Hello Alberto.

I am afraid I can't offer you any advice since your knowledge is greater than mine but please accept my condolences for your loss.

Best regards.

Paco

[albertofenini]

You wouldn't believe how we fixed it (at least the reading)...
We tried another Standard Pac, simply because working on another HP67 we had some trouble in reading the cards that we usually use for our tests ...
Now it reads
However, the last column of keys is not working, nor it goes into programming mode ...
We had noticed that the keyboard PCB had some traces kind of cut, but at the time we didn't pay too much attention to this,
we will reopen it and try to fix this ...
Thanks to everyone !